Machine for forming and sharpening drill-bits and the like.



H. J. H. NATHORST & G. LUNDSTRUM. MACHINE FOR FORMING AND SHARPENINGDRILL BITS AND THE LIKE.

APPLICATION FILED JAN. 3, 1911. 1,023,476.

Patented Apr. 16, 1912.

2 SHBETSSHEET 1.

COLUMBIA l'LnNuukAPH 60.,WASHINOTON, D. c.

V H. J. H. NATHORST & G. LUNDSTRUM. MACHINE FOR FORMING AND SHARPENINGDRILL BITS AND THE LIKE.

APPLICATION FILED JAN.3, 1911. Patented Apr. 16,

2 8HBETS-SHEET 2.

I/I/IIIIM wit n eases COLUMBIA PLANOGRAPH CO-.\VASIHNGTON. n. c.

UTTED ST non.

OF GELLIVARE MALMFALT, SWEDEN.

MACHINE FOR FORMING AND SI-IARPENING DRILL-BITS AND THE LIKE.

To all whom it may concern:

Be it known that we, HARRY J OHAN TTJAL- MAR Na'm'onsr and GO'ITHARDLUNns'rRoM, subjects of the King of Sweden, residing at GellivareMalmfalt, Malmberget, Sweden, have jointly invented new and usefulImprovements in Machines for Forming and Sharpening Drill Bits and theLike, of which the following is a specification, reference being had tothe drawings accompanying and forming a part hereof.

This invention relates to a machine for forming or sharpening cuttingedges on drill bits or other similar tools according to the methodforming the subject-matter of my application for patent Ser. No.531,806, filed Dec. 7, 1909.

In forming or sharpening cutting edges on drill bits and the like,especially cruciform drill bits, co-called star bits, used in rockdrills, it has been usual to repeatedly heat the drill bit and work thesame in the machine. This procedure is time-wasting and disadvantageousin respect of the durability of the drill bit.

The object of this invention is to provide a machine by means of whichthe cutting edges of the drill bit or the like may be formed or thesharpening effected with less labor and in one heating, and theinvention consists in the combination of known elements hereinafter setforth and claimed.

In the drawing, we have shown a machine embodying the invention.

Figure l is a side view of the whole machine. Fig. 2 is a plan View ofthe same. Fig. 3 is a central longitudinal section "of the sharpeningmachine proper which operates the end of the drill bit for forming thestar. Fig. a is a cross-section of the same on line AA in Fig. 3. Fig. 5is a plan View of the same.

Referring to Figs. 1 and 2 of the drawings, 1 is a standard placed on abottom plate 2. Mounted on the said standard are a guide 3 for thesharpening machine, a frame at for the machine operating the end of thedrill bit laterally, an anvil 5 cooperating with the hammer 6 of thesaid machine, and a beam 7 preferably U-shaped in cross-section andserving to support the drill bit and the adjustable abutment 8 for thesame.

The sharpening machine proper is shown on a larger scale in Figs. 3 to5. It is shown mounted on a slide 9 movable along the Specification ofLetters Patent.

Application filed January 3, 1911.

Patented Apr. 16, 1912. Serial No. 600,633.

guide 3. Placed at the ends of the said slide 9 are supports l0, 11 forthe sharpening machine, preferably a pneumatic hammer machine of' anysuitable type, such as the wellknown Flottmann type. Movable in thecylinder 12 of the said machine is a piston 13 having a part 1% of lessdiameter extendng to the stamp 15, said stamp being rigidly attached toa sleeve 16 having longitudinal lists or ribs engaging correspondinggrooves 17 in the forward part of the pis ton. The distribution of thecompressed air is controlled in usual manner by a valve 18 cooperatingwith the exhaust openings 19 in the cylinder 12.

The part 14. of the piston is provided, behind the grooves 17, withwindings 20 of very large pitch engaging corresponding windings in aratchet sleeve 21 surrounding the said part of the piston. The sleeve 21is provided at its periphery with ratchet teeth engaged byspring-actuated pawls 22 in such a manner that the said sleeve is freeto turn when the piston moves forward (toward the stamp), whereas it islocked in position when the piston moves backward so as to cause thepiston and, thereby, the sleeve 16 surrounding the fore part of thepiston, and the stamp 15 secured to the said sleeve 16, to turn an anglecorrespmnding to the pitch of the windings 20. It will thus be seen thatthe stamp 15 is turned a certain angle each time the piston recedes fromthe same.

The slide 9 is provided with arc-shaped guides 23, 24 for the supportsso that the cylinder may be placed in a desired inclined positionrelatively to the longitudinal direction of the drill bit operated upon.The cylinder is secured in position by a thumbscrew 25 passing throughan oblong slot in the rear support 11 and screwed into the rear guide241. The supports 10, 11 are shown connected by rods 26 and springs 27.

The slide 9 is moved longitudinally by means of a lever 28 (Fig. 1)connected by a link 29 to the slide or by means of a treadle 30connected by a rod 31 to a lever arm 32 pivoted at 33 and connected by alink 3-1 to the lever 28. By this means the stamp 15 may be kept pressedagainst the drill bit during working.

A crank arm 35 connected to the plug of a cock is used for opening orclosing the pressure conduit.

The hammer 6 forms part of a pneumatic hammer machine of any suitableconstruction, such as an ordinary piston rock drill. A treadle 36 (Fig.2) is connected by a rod 37 (Fig. 1) to a crank arm 38 connected to theplug of a cock for controlling the supply of pressure fluid.

The abutment 8 for the drill bit is connected by a chain 89 running onrollers 4:0 to a chain-wheel a1. Connected to the said chain-wheel is aratchet wheel 42. This ratchet wheel and thereby the chain-wheel may beturned by a crank 43 in one or the other direction according to theposition of the adjustable ratchet pawl 4-4:.

The machine works as follows: The drill bit to be operated upon isplaced with its heated end in the anvil 5, and the abutment 8 is movedby the crank i3 into a position in which it abuts with the rear end ofthe drill bit. The stamp 15 of the sharpening machine, which has beforebeen placed in the desired angle relatively to the longitudinaldirection of the drill bit, preferably an an gle of about 5, is moved bythe lever 28, or the treadle 30, into close contact with the fore end ofthe drill bit. Thereupon the crank 35 is operated to admit pressurefluid to the cylinder of the sharpening machine by which the piston iscaused to reciprocate very rapidly so as to make impacts upon the stampand cause the same to cut into the drill bit. After each impact upon thestamp the latter is automatically turned a certain angle and, on accountof its engagement with the drill bit, causes the latter to turn with it.By this means the cutting edges are rapidly formed, Withoutnecessitatingthe drill bit to be reheated. WVhen the cutting edges are finished, thesharpening machine is thrown out of action and the hammer 6 is throwninto operation for compressing the drill bit laterally.

WVe claim:

In a machine for forming and sharpening cutting edges on drill bits andthe like, the combination of a rotatably mounted stamp, means forsubjecting the said stamp to pressure to impart longitudinal movementthereto, means for rotating the said stamp during working, and means forrotatably holding the drill hit up to the said stamp, at an angle to thesame.

HARRY JOHAN HJALMAR NATHORST. GOTTHARD LUNDSTRGM. Vitnesses:

G. N. FRIs'rnDT, E. L. A. BJORKMAN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington. D. C.

